OK I was never looking for this, but got it for a reasonable price. CZ made Co2 pistol, apparently model APP 661. Looks like the designer was having a Nambu dream when he designed it. Real solid. Blued steel barrel, some sort of alloy frame that has taken on the appearance of old parkerised steel. Some milling marks on it. Got some gas carts for it, but have no idea how to load ammo, what the button and tab do, etc. Has adjustable sights too. Seller had no info. What have I got? Need any info on it. Tnx! Hope they don't toss me off this as it is not really a firearm?